Platelet preparations are administered for the purpose of treating and preventing the symptoms of patients experiencing heavy bleeding during surgery or injury, or patients exhibiting a bleeding tendency associated with decreased platelets following anticancer drug treatment. At present, production of platelet preparations relies on blood donations from healthy volunteers. However, the number of blood donors in Japan is decreasing for demographic reasons, and it is estimated that by 2027 there will be a shortage of about a million donors. Therefore, securing a stable supply of platelets is an objective in the technical field of the present invention.
Moreover, because conventional platelet preparations are at high risk of bacterial contamination, there is a danger of serious infections occurring after transplantation of platelet preparations. Therefore, there is always a clinical demand for safer platelet preparations. To meet this demand, methods are now being developed for producing platelets from megakaryocytes cultured in vitro.
Conventionally, production of platelets from cultured cells has been performed in a stationary culture system using a dish (WO 2014/100779A1, Qiang Feng et al., Stem Cell Reports). However, stationary culture systems are extremely labor-intensive and have not been suited to large-scale culture.